The present invention relates to a fastening device for reversibly assembling a first vehicle component and a second vehicle component. Besides, the present invention relates to a fastening method, for reversibly assembling a first vehicle component and a second vehicle component.
Document DE102008033110A1 discloses a fastening device for reversibly assembling two components and including a male part, a female part presenting an opening for inserting the male part and two engaging balls movable between a locking position and a releasing position. Each engaging ball is biased by a spring towards the locking position. The male part has a circumferential groove for partly receiving the engaging balls. In the locking position, the engaging balls are engaged in the circumferential groove in order to retain by abutment the male part.
In DE102008033110A1 to move the engaging balls in a release position, it is necessary to pull back the male part from the female part of the fastening device, in order to disengage the engaging balls from the circumferential groove and to overcome the biasing force generated by each spring. A main drawback of the fastening device DE102008033110A1 is that the biasing force required to lock the fastening device must be strong enough to maintain both the male part and the female part in an assembled state, whereas in the other side this biasing force should not be too strong, in order to allow disassembling of the male part and the female part. Therefore, in DE10200803311 it is not possible to achieve both a strong fastening and an easy disassembling process.
For instance, the fastening device of DE102008033110A1 is not suitable to fasten various vehicle components, in particular dashboard components, which request a reliable assembling to withstand for instance vehicle vibrations, but which must also be easily removable in particular for maintenance.
Besides, since the fastening device of DE102008033110A1 has a complex structure, in particular due to the radial arrangement of its locking elements (i.e. engaging balls, springs . . . ), the fastening device of DE102008033110A1 cannot achieve a strong fastening together with a compact design.
It therefore appears that, from several standpoints, there is room for improvement in the panel frames of a vehicle.
It is desirable to provide a fastening device enabling an operator to quickly and reliably assemble by hand a first vehicle component and a second vehicle component.
A subject-matter of the invention is a fastening device, for reversibly assembling a first vehicle component and a second vehicle component, wherein the fastening device includes at least:
a male part suitable for being secured to a first vehicle component, for example a dashboard, the male part comprising a plate member,
a female part suitable for being secured to a second vehicle component, for example a dashboard component, said female part presenting a slot suitable for the insertion of said plate member,
at least one friction retainer comprising a friction zone, the friction retainer being movable at least between:
a locking position, in which said at least one friction zone is in frictional engagement with said plate member when said plate member is inserted through said slot, and
a releasing position, in which said at least one friction zone is not in frictional engagement with said plate member such that said plate member may be removed from said slot,
at least one biasing component arranged to bias said at least one friction retainer towards the locking position such that said friction zone is in frictional engagement with said plate member so as to prevent said plate member from moving relative to said slot, wherein said at least one friction retainer is at least partially composed of a magnetic material such that a predetermined magnetic force can move said at least one friction retainer towards the releasing position and against a biasing force generated by the biasing component.
Thus, such a fastening device enables an operator to reliably assemble a first vehicle component and a second vehicle component by hand, hence without any tool. The frictional engagement generates a “locking force” between these vehicle components. Besides, such a fastening device enables an operator to disassemble these vehicle components using solely a magnetic tool that can be part of the fastening device or distinct from the fastening device. The assembling step only requires the operator to push the male part through the slot of the female part. Quick and easy assembling and disassembling help decrease the production costs.
Besides, the use of the plate member of the present invention allows the fastening device to withstand high traction forces while preserving a compact design.
Throughout the present application, the expression “magnetic materials” refers to any material able to generate, under a predetermined magnetic force, a magnetic coupling stronger than the forces exerted by the biasing component. Thus, the predetermined magnetic force can move the friction retainer(s) against the forces exerted by the biasing component(s). Examples of magnetic materials may be, for instance, a ferromagnetic material.
According to the invention, the magnetic material is preferably selected in the groups consisting of neodyme-fer-bore alloys or AlNiCo alloys. Preferably, the friction retainer is comprised of a magnetic material, whereas at least the male part and the female part of the fastening device can be composed of non-magnetic materials.
According to an embodiment, said at least one friction zone extends substantially along a friction line.
Thus, such a friction line defines a relatively large friction zone, which enables the fastening device to generate a large “locking force” or, in other words, to withstand a high traction force exerted upon the male part.
According to an embodiment, said at least one friction line is straight, wherein said plate member has a planar friction area arranged to cooperate with said at least one friction zone to generate a friction force that provides a locking force able to withstand a high traction force exerted upon the male part, and wherein said slot has a substantially rectangular form.
Thus, such a rectilinear friction line and planar friction area make it possible to design a fastening device with simple, hence cheap parts or components.
According to an embodiment, said plate member has a substantially rectangular cross-section, across a plane perpendicular to the insertion direction of the plate member into said slot, said rectangular cross-section having a length over thickness ratio greater than 4, preferably greater than 8.
Thus, such a length over thickness ratio imparts the fastening device a high tensile strength so as to generate a large “locking force” yet with limited impact on the overall dimensions of the fastening device.
According to an alternative embodiment, said at least one friction line is curved, said slot being curved, each friction retainer has a substantially ellipsoidal shape, and said plate member has a cylindrical friction area arranged to engage with said at least one friction zone. Thus, such a curved friction line enables to increase the area of the friction zone.
According to a variant, said at least one friction zone is continuous along said friction line. Thus, such a continuous friction zone enables the fastening device to maximize the “locking force” while keeping a short plate member.
According to an embodiment, said at least one friction retainer is located in the female part.
Thus, the fastening device can be closed, which prevents any unexpected foreign matter to block the movement of the friction retainer(s). Besides, thanks to this arrangement, the fastening device can be optimized so that it can be compact and have small overall dimensions.
According to an embodiment, the fastening device includes at least two friction retainers, each friction retainer being located on either side of said slot.
Thus, two friction retainers enable the fastening device to generate a stronger “locking force”.
According to an embodiment, said at least one biasing component is connected to the female part and is preferably arranged inside the female part.
Thus, the fastening device can be quite compact, as the fastening device does not require any supplementary part between the biasing component and the female part. Throughout the present application, the term “connected to” and its derivatives refers to any direct or indirect mechanical connection, namely through zero, one or more intermediate component. Throughout the present application, the term “bias” and its derivatives refers to any direct or indirect generation of a biasing force, namely through zero, one or more intermediate component.
According to an embodiment, said at least one biasing component comprises at least one spring arranged to bias said at least one friction retainer, preferably in a biasing direction substantially perpendicular to said slot, said at least one spring preferably being a compression helicoidal spring.
Thus, the spring(s) form a biasing component which is simple and inexpensive to manufacture and assemble.
Preferably, the movable parts, comprising said at least one friction retainer and said at least one biasing component, are movable according to a direction that is substantially parallel to an insertion direction of said male part through said slot.
This arrangement contributes to the compactness of the fastening device.
According to a variant, the fastening device further includes a cover located on the female part and opposite said slot, said cover forming an abutment for each spring. Thus, such a cover ensures a correct location for the spring(s) while the fastening device has a relatively small number of components.
According to an embodiment, the fastening device further includes a pressure element arranged inside the female part between said at least one biasing component and said at least one friction retainer so as to transmit forces from said at least one biasing component to said at least one friction retainer, said pressure element being slidable according to a direction that is substantially parallel to an insertion direction of said male part through said slot.
Thus, such a pressure element achieves a distribution of the biasing force from the biasing component onto a large area of the friction retainer(s). Besides, the pressure element may help guiding the biasing component and/or the friction retainer(s).
According to an embodiment, said at least one friction retainer comprises a cylinder having a circular cross-section and extending substantially parallel to said slot, said cylinder being free to move inside said female part when said friction retainer lies in the releasing position.
Thus, such a cylinder provides a friction retainer which can generate a large “locking force” while allowing an easy insertion of the plate member through the slot.
According to an embodiment, the fastening device further includes at least one guide part arranged to guide said cylinder towards said slot.
Thus, such a guide part helps distributing compression by the biasing component(s) on the cylinder(s). The guide part may also prevent any unexpected displacement of the cylinder(s), which could lead to a jamming or overhanging position of the cylinder(s). The guide part(s) can guide the cylinder(s) towards the slot when the biasing component biases the friction retainer(s) towards the locking position.
According to a particular embodiment, the fastening device further includes at least two guide parts, wherein each friction retainer comprises a cylinder extending substantially parallel to said slot, guide parts extending on either side of said slot to guide a respective cylinder when it moves from the releasing position to the locking position, that is to say, when it moves towards said slot.
Thus, two cylinders and guide parts enable the fastening device to generate a double “locking force”.
According to an embodiment, said at least one guide part comprises a wall of the female part, said wall defining a gap progressively narrowing towards said slot, preferably said wall progressively curving towards said slot.
According to a variant, said at least one guide part comprises a concave surface of the pressure element facing said slot. Thus, such a concave surface enables to efficiently guide the friction retainer(s).
According to an embodiment, a primary ratio where:—the numerator is the radius of said at least one cylinder, and the denominator is the thickness of the rectangular cross-section of the plate member that is greater than 1, preferably greater than 2.
Thus, such a primary ratio enables the fastening device to generate a large “locking force”.
According to another embodiment, said at least one friction retainer comprises an arm extending parallel to said slot, each arm being arranged to pivot with respect to the female part about an axis substantially parallel to said slot.
Thus, such an arm enables the fastening device to generate a large “locking force”, while its pivoting arrangement enables an easy insertion of the plate member through the slot.
According to a variant, the fastening device further includes at least a hinge for each respective arm, each hinge preferably linking a respective arm to the female part. Thus, such a hinge allows the pivoting movement of the friction retainer made of an arm.
According to a variant, the or each arm is formed by a rectangular plate and said hinge is located on one edge of said rectangular plate. Thus, such an arm is easy and inexpensive to manufacture and to assemble.
According to a variant, the or each arm is designed so as to maximize the surface of contact between said plate member and a respective friction zone. Thus, such an arm enables the fastening device to generate a maximal “locking force”.
According to an embodiment, each friction retainer comprises a corresponding arm extending parallel to said slot.
Thus, two retainers enable the fastening device to generate a double “locking force”.
According to an embodiment, said at least one biasing component comprises at least one torsion spring arranged to bias said at least one friction retainer in a biasing direction substantially perpendicular to said slot, said at least one torsion spring preferably being a torsion helicoidal spring.
Thus, such a torsion spring ensures the movement of the friction retainer returning to its locking position.
According to an embodiment, said friction zone is defined by a rounded edge of said arm.
Thus, such a rounded edge ensures a large area of the friction zone, which in turn ensures a large “locking force” for the fastening device.
According to an embodiment, said at least one arm is designed to define, in its locking position, a lock gap having a width smaller than the width of said slot when measured perpendicularly to the insertion direction of said plate member.
Thus, such a lock gap enables the arm to generate a large “locking force”.
According to an embodiment, said plate member and said at least one arm are designed such that, in the locking position, the angle between the arm and a direction perpendicular to the plate member is in the range of 5 to 25°.
Thus, such an angle allows the plate member to be locked in the slot against removal forces when the or each friction retainer is in the locking position, while such an angle allows an easy removal of the plate member when the or each friction retainer is in the releasing position.
According to an embodiment, the fastening device further includes at least one magnet manually movable between:                a lock position, in which the magnetic force exerted by said at least one magnet on said at least one friction retainer is substantially smaller than the biasing force exerted by said at least one biasing component on said at least one friction retainer, so that said at least one friction retainer is kept in its locking position, and        a release position, in which the magnetic force exerted by said at least one magnet on said at least one friction retainer is substantially greater than the biasing force exerted by said at least one biasing component on said at least one friction retainer, so that said at least one friction retainer is moved towards its releasing position.        
Thus, such a magnet makes it possible to easily remove the plate member from the slot, thus to disassemble the vehicle components.
According to a variant, the fastening device includes at least two magnets. Thus, two magnets ensure that the friction retainer(s) will not unwittingly move to the releasing position. Indeed, it takes two magnets at suitable locations to release the plate member.
Said at least one magnet can be located on a side surface of the fastening device that is opposite to the slot with respect to said at least one friction retainer. Preferably, said at magnet is located on the cover of the fastening device, Thus, such a magnet location enables an easy release of the friction retainer(s), hence an easy removal of the plate member. Preferably said at least one magnet is fixed on said side surface of the fastening device in a sliding manner to be manually moved between the lock position and the release position.
According to a variant, said at least one magnet is part of a supporting member or part of a holding plate tool that is distinct from the fastening device.
Another subject-matter of the invention is a fastening method, for reversibly assembling a first vehicle component and a second vehicle component, wherein the fastening method includes the steps of:
supplying a fastening device according to any preceding embodiment, inserting said plate member into said slot until said at least one biasing component has moved said at least one friction retainer in its locking position.
These and other features and advantages will become apparent upon reading the following description in view of the drawings appended thereto, which represent, as non-limiting examples, embodiments of a fastening device according to the invention.